A filter element used, for example, as a motor vehicle indoor air filter or as a filter element for an air conditioner of a motor vehicle, serves to filter conditioned air passed from the outside into the vehicle interior. For this purpose, for example, particle or odor filters or a combination thereof are employed, which out-filter the particles and inherent odors from the ambient air. In this instance, the effectiveness of a filter or of such a filter system also depends on whether the filter system is installed in the right position in the filter housing or in an assigned filter reception of the filter housing.
A filter assembly for filtering supply air of a motor vehicle is known from the publication DE 10 2009 041 113 A1 in which flaps project at opposite situated longitudinal sides and are pivotably hinged at the filter medium. The filter element is snapped into the top part of a filter housing on the clean air side in such a manner that the flaps sealingly abut at the housing walls. In this instance, the free ends of the flaps point against the flow direction of the air. For this reason, air inflowing from the direction of the inflow side can pivot the movable flaps about their fixed end and press them by their free ends against the housing walls. In this instance, flaps made of a nonwoven fabric are used. Furthermore, the flaps made of nonwoven fabric provide a filter medium which additionally filters the supply air to the motor vehicle engine.